Antiherpesvirus activity of the combination of 5-iodo-2' deoxycytidine with methotrexate : an in vitro and in vivo study

We evaluated the in vitro and in vivo antiviral activity of the deoxyribonucleoside analogue 5-iodo-2'-deoxy-cytidine (IDC) combined with the dihydrofolate reductase inhibitor methotrexate (MTX) on herpes simplex virus types 1 and 2 (HSV-1, HSV-2). The IDC-MTX combination synergistically inhibited HSV-1 and HSV-2 replication in vitro at concentrations that did not reduce cellular viability and was very effective in reducing the severity of cutaneous lesions in the experimental guinea pig model in vivo. The antiviral activity of the IDC-MTX combination in guinea pigs was also compared with that of acyclovir and was demonstrated to be higher.